Abstract

We describe the twisted affine superalgebra sl(2|2)(2) and its quantized version Uq[sl(2|2)(2)]. We investigate the tensor product representation of the four-dimensional grade star representation for the fixed-point subsuperalgebra Uq[osp(2|2)]. We work out the tensor product decomposition explicitly and find that the decomposition is not completely reducible. Associated with this four-dimensional grade star representation we derive two Uq[osp(2|2)] invariant R-matrices: one of them corresponds to Uq[sl(2|2)(2)] and the other to Uq[osp(2|2)(1)]. Using the R-matrix for Uq[sl(2|2)(2)], we construct a new Uq[osp(2|2)] invariant strongly correlated electronic model, which is integrable in one dimension. Interestingly this model reduces in the q = 1 limit, to the one proposed by Essler et al which has a larger sl(2|2) symmetry.